Unless otherwise indicated herein, approaches described in this section are not prior art to the claims listed below and are not admitted to be prior art by inclusion in this section.
Portable electronic apparatuses such as smartphones and tablet computers are typically equipped with multiple functions and features. Often times the multiple functions and features are implemented in the form of a main integrated circuit (IC) chip and one or more external components coupled to the main IC chip, where each of the external components may respectively operate on one or more multiple voltages and/or at one of multiple clock rates, depending on the respective configuration setting. That is, multiple clocks are provided in a portable electronic apparatus for the operations of the multiple external components to provide the multiple functions and features.
Dynamic voltage and frequency scaling (DVFS) is a power management technique in computer architecture for adjustment of operating voltage and/or frequency, or clock rate, of an electronics component such as an IC chip. In a portable electronic apparatus with a main IC chip and one or more external components coupled thereto, each of which respectively operating at one or more voltages and/or one or more frequencies, there is a need for coordination in changes made for DVFS adjustment between the main IC chip and the one or more external components. Moreover, changes in operating voltage and/or frequency may be triggered by software commands and/or hardware signals. However, with frequent changes in operating voltage and/or frequency and configuration setting, e.g., by hardware signals, there tends to be a loss in efficiency.